import html2canvas from 'html2canvas'
import jsPDF from 'jspdf'
export const downloadPDF = (page,name) => {
  html2canvas(page).then(function (canvas) {
    canvas2PDF(canvas,name);

  });

};

const canvas2PDF = (canvas,name) => {
  let contentWidth = canvas.width;

  let contentHeight = canvas.height;

  //a4纸的尺寸[595.28,841.89]，html页面生成的canvas在pdf中图片的宽高

  let imgWidth = 595.28;

  let imgHeight = 592.28 / contentWidth * contentHeight;

  //let imgHeight = 700/contentWidth * contentHeight;

  //一页pdf显示html页面生成的canvas高度;

  var pageHeight = contentWidth / 592.28 * 841.89;

  let totalHeight = contentHeight;

  // 第一个参数： l：横向  p：纵向

  // 第二个参数：测量单位（"pt"，"mm", "cm", "m", "in" or "px"）

  let pdf = new jsPDF("p", "pt");

  let position = 0;

  //   pdf.addImage(

  //     canvas.toDataURL("image/jpeg", 1.0),

  //     "JPEG",

  //     0,

  //     0,

  //     imgWidth,

  //     imgHeight

  //   );

  if (totalHeight < pageHeight) {
    pdf.addImage( canvas.toDataURL("image/jpeg", 1.0), 'JPEG', 0, 0, imgWidth, imgHeight);

  } else {

    while (totalHeight > 0) {
      pdf.addImage( canvas.toDataURL("image/jpeg", 1.0), 'JPEG', 0, position, imgWidth, imgHeight)

      totalHeight -= pageHeight;

      position -= 841.89;

      //避免添加空白页

      if (totalHeight > 0) {
        pdf.addPage();

      }

    }

  }

  // pdf.addImage(

  //     canvas.toDataURL("image/jpeg", 1.0),

  //     "JPEG",

  //     0,

  //     position,

  //     imgWidth,

  //     imgHeight

  // );




  pdf.save(name+".pdf");

};
